Kınalıada (Greek: Proti and Akoni) is one of the Princes' Islands in the Marmara Sea near Istanbul and is the closest island to Istanbul’s port with the distance of 6.5 miles. Its distance to the Anatolian side of Istanbul is 3.5 miles. Its colour comes from its reddish soil which is also where the island took its name as “Kınalıada” means "Henna Island."

Kınali Island is almost 1.5 km in length and the width of the island is 1.1 km. It is the fourth largest of the Princes' Islands in the Marmara Sea. There are three large hills on the island. They are Çınar Hill, located on the western part of the island, Teşvikiye Hill (115 meters), located next to Çinar Hill, and Hristo Peak (93 m), on top of which is Hristo Monastery. During the Byzantine period, the island most used as a place of exile (the most notable exile being the former Emperor Romanos IV Diogenes after the Battle of Manzikert in 1071). It is rumoured that the grave of the Romanos IV Diogenes is located next to the present orphanage. Manastır Bay is located on the western side of the Hristo Hill. There are both big and small mining holes on the northern section of Manastır Bay, which draw the attention of the visitors.

The climate of the Kınalıada is harsher than that of the other islands. It does not have a significant amount of woodland, but it does has a stone-rich environment. The Byzantine Walls were built with these stones, cut out from the quarry on the island during the Byzantine time and they were also used for building the Tophane Dock and Haydarpaşa Port in the 19th century. Because the climate of the island is harsh and has a limited woodland, summer house vacationists of Istanbul have not been interested in this island. After 1833, the first Armenian population settled on the island and with the initiation of ferry services in 1846, they become the dominant population on the island. After they settled on the island, they built the Surp Krikor Lusavoriç Armenian Church and the Nersesyan Armenian School in 1857 which played a key role in vitalizing the island. Ethnically, it is a cosmopolitan island with a population of 3,943 in 1990. In 1997, the population in the island decreased to 2,539 and in 2000, it rose to 3,318.

The major buildings built by the Greek minority on the island are the Orthodox Panayia Church and the Greek Elementary School built in 1869, and classesin the Turkish Elementary School on the island began in 1935. The other place of worship on the island is for Muslims is the Kınalıada Mosque which has a different architectural design and was built in 1963.

There was no water or electricity in the island’s houses until 1947, when electricity arrived to the island’s homes. Islanders were provided with clean water from cisterns. In 1981, the water shortage problem in the island was solved by building a water distribution network connected with the mainland.